Hilchos Maasei Hakarbanos 1:11

Peace offerings are brought from sheep, goats or cattle, male and female, large and small. A bird is not brought as a peace offering. When an animal is called “small,” that means from eight days old to a full year, counting day to day. If the year is declared to be a leap year, the leap month is counted. “Large” when it comes to cattle means until three full years, counting day to day. For flocks, it means until two full years counting day to day. After these ages, the animal is considered old and may no longer be offered.

Hilchos Maasei Hakarbanos 1:12

While any of these offerings are fit if brought from the eighth day on, we optimally do not offer an animal until it is at least thirty days old with the following exceptions: a firstborn animal, the korban Pesach and animal tithes. If a person wants to offer one of these from the eighth day on, he may do so.